Female urinary stress incontinence is a pathology affecting more than ten percent of the female population over age 60. The pathology results from either one or both of the following anatomical conditions: 1) abdominal straining causing urethral hypermobility; 2) urethral intrinsic sphincter deficiency (ISD), which is the inability of urethral musculature to completely close the urethra or keep it closed during stress. The surgical procedures to correct these pathologies are dependent on whether urethral hypermobility or ISD is the predominant pathology. In the case of urethral hypermobility, incontinence is corrected by prevention of urethral descent during stress and/or abdominal straining. In the case of ISD, correction is accomplished by increasing the passive pressure applied on the urethra so as to increase its passive resistance to urine passage. Failure to determine the correct type of incontinence results in the performance of an inappropriate surgical procedure with subsequent unsatisfactory surgical success and subsequent complications.
To properly establish the type of urinary incontinence, two factors must be determined: 1) urethral descent during straining, which may be determined by measurement of the spatial angular change of the urethral axis (herein called the urethral angle change) during straining and 2) leak point pressure, the minimal vesical pressure at which urine leaks through the urethra. Low leak point pressure characterizes ISD. A common method in the art to evaluate urethral angle change is by installing a "rod" into the urethra with the physician estimating the rod axis angle change by visual examination. Leak point pressure is generally established during urodynamic evaluation by the placement of a pressure measuring catheter in the bladder with the physician recording the pressure at which urine leakage through the meatus is visually detected. Both these testing methods lack objectivity and accuracy in obtaining results. There is therefore a need for an invention which provides a more objective and accurate measurement of urethral angle change and leak point pressure concomitantly.